Its possible that the stones you call lecithin stones were actually coated in what some flushing protocols call "chaff". Chaff is waxy tan, or sometimes yellow or light green, flakes of choloesterol that clog the biliary ducts. I have had many flushes where the green stones where coated in chaff and so far do not take lecithin. (I bought some, but it was already rancid when I got it-nasty stuff and I haven't gotten the courage to try more)
There have been flushes where I passed two or more cups of the chaff that floated on top of the water, but only had a few stones.
This waxy substance does clog the ductwork in the liver and reduces the flow of bile. Its a very good thing to get out. Congratulations on a good flush.